Field of the Invention
The present invention relates to a wireless power transmission system, a furniture having a wireless charging function used therein, and a wireless power transmission apparatus used therein capable of conveniently charging a portable electronic device such as a smart phone, or the like.
Description of the Related Art
Generally, a battery pack supplies an operation power to a portable electronic device (such as a cellular phone, personal digital assistant, or the like). The battery pack is charged by receiving a power (such as electric energy) from an external charger, and is configured to include a battery cell in which the electric energy is stored, a circuit for charging and discharging (that is, supplying the electric energy to the battery cell, and from there to the portable electronic device), and the like.
To electrically connect a charger to the battery pack, thus charging the battery pack with electrical energy, one possible method is a terminal supplying scheme: namely, receiving a commercial power, converting the commercial power into a voltage and a current appropriate for the battery pack, and supplying the electric energy of the converted power to the battery pack through terminals of the battery pack.
However, when power is supplied using the terminal supplying scheme, as the charger contacts the battery pack or is separated from the battery pack, a terminal of the charger and a terminal of the battery pack may have different potential differences, which may cause an instantaneous discharging phenomenon.
Importantly, when foreign materials have accumulated on these terminals, there is a risk that a fire or the like will occur due to the instantaneous discharging phenomenon.
In addition, the electric energy charged in the battery pack is naturally discharged to the outside environment through the terminal of the battery pack due to moisture or the like, such that a lifespan of the battery pack may be decreased and performance thereof may be deteriorated.
In order to solve these problems, contactless charging systems and control methods using a wireless power transmission scheme have been recently suggested.
In particular, attempts to apply the contactless charging system to electronic devices that need to be charged frequently (e.g. smart phones, tablets, laptop personal computers, or the like) have been conducted. Since a battery should be frequently charged, especially in a smart phone which is often running various applications, users have recently felt the need to carry a separate charging battery (external battery), which is inconvenient. A convenient charging method is therefore preferable.
However, a charger is not always conveniently available, or the user may not think about the need to charge the smart phone, even when the smart phone is not being otherwise used. Therefore, there is a need for a system which simply and conveniently charges a battery pack of a smart phone when the user does not use the smart phone for a while.